After the other replies giving advice, that's about all I have to offer for the short-term.

Long-term, try and make friends with a mechanic or get on friendly terms with a repair place you trust who will recommend other shops for different types of work done.

My wife and I go to a mechanic who's saved us hundreds of dollars in the last few years and sends us to people he knows will do the job well, and quickly. This has proved itself just recently as we were rear-ended last week. We were recommended to a body shop who fixed our bumper/replaced a bunch of stuff and returned the car the very next day.